Heat exchanger for oil coolers



y 1942- H. F. B RINEN 2,289,097

HEAT EXGHANGER FOR OIL COOLERS Filed May 9, 1941 1N VEN TOR. H0m420fi'Bem /Y BY as A 7' TOE/YE Y Patented July 7, 1942 HEAT EXCHANGER FOBOIL COOLERS I Howard F. Brlnen, Racine, Wis., assignor to Young RadiatorCompany, Racine, Wis., a company of Wisconsin Application May 9, 1941,Serial No. 392,705

3 Claims.

The present invention relates to means for controlling the temperatureof internal combustion engine lubricating oil and is particularlyadapted for use with aviation engines and is offered as an improvementover the design shown in a pending application John J. Hilt inventor,Serial No. 364,236, filed November 4, 1940.

An object of the present invention is to provide a conventional designhaving two headers and a number of preferably similar tubes formingoperating connections therebetween and a multiplicity of closely spacedstrip fins through which the tubes extend forming a unitary core.

Another object'of the present invention is to provide a conventionaldesign having means whereby the lubricating oil is first passed throughlow resistance low heat transfer capacity tubes while at low temperatureand then through a large number of high resistance tubes after the oilreaches a predetermined temperature.

The above objects are accomplished by providing a unitary core having afew front tubes of low heat transfer capacity and ofiering lowresistance to the flow of oil therethrough and a large number of highresistance tubes in the rear and a partition between the front and reartubes in one of the headers having a valve adapted to permit the oilwhen too viscous to pass through the high resistance tubes to passthrough the low resistance tubes.

In my new design, I use tubes in the rear bank of tubes which arepreferably similar to the front tubes but are provided with turbulencestrips. In order to provide a high resistance path, I may provide alarge number of very small tubes so hot oil will flow therethroughfreely but the oil will not flow therethrough when chilled. Therefore itmay be said that the lubricating-oil will be permitted to heat quicklyafter which it will pass through the rear bank of tubes and beeffectively cooled.

Another object of the present invention is to position the lowresistance tubes in a transverse row at the air entrance or front sideof the device and arrange the'by-pass valve so when the oil will notpass through the high resistance tubes, it will raise the valve and bepermittedto pass through these low resistance tubes.

A further object of the present invention is to provide means wherebythe oil will be permitted to heat quickly because of the limited numberof tubes through which it first passes and the limited cooling areaexposed to the air but to percontact with the high resistancetubes andtheir portions of the fins.

A still further object of the present invention is to provide a devicefor the purpose which will be unitary, compact, light, neat inappearance and durable which can be manufactured at low cost.

Another object of the present invention is to provide an aperture in thevalve partition whereby a predetermined volume of oil will be permittedto pass from the high resistance end of the header to the low resistanceend of the header when the valve is closed; thus .to utilize the lowresistance tubes and their portion of the fins to cooperate with thehigh resistance tubes in normally cooling the oil.

To these and other useful ends, my invention consists of parts,combinations of parts, or their equivalents and mode of operation, ashereinafter set forth and claimed and shown'in'th accompanying drawingin which:

Fig. 1 is a front view of my improved oil cooling device. a

Fig. 2 is a transverse sectional view of the device shown in Figure 1,taken on line 2-2 of this figure.

Fig. 3 is an end view of one of the high resistance tubes and theagitating means therein,

Fig. 4 is a longitudinal section through a fraction of one of the highresistance tubes, illustrating the agitating means therein.

Fig. 5 is a view of the agitating means before the body is zig-zagged asshown in Figure 4.

Fig. 6 is a sectional view of a modification taken on line 5-6 of Figure7. a

Fig. 7 is a longitudinal sectional'v'iew of th modification shown inFigure 6.

As thus illustrated, my improved device co prises a lower header l0 andan upper header! i, the lower header being conventional and the upperheader being equipped with a partition i2 arranged between the lowresistance row of tubes and the high resistance bank of tubes.

Partition I2 is shaped as shown and provided with preferably a forwardlycurved projection lz having an aperture l2 and an opening l3 formed witha seat as at I5 for a valve Hi, the valve having a stem l6 which isslidably mounted in a cap IT. as illustrated, the cap being screwthreaded into an extension chamber l8 which is concentric with openingl3 and registering with member 82 I provide a spring is for holding thevalve on its seat against a predetermined pressure.

mit the heated air to then come in heat exchange The headers areoperatively connected together by means of preferably a front row ofcircular in cross section tubes 20 and a number of rows of circular incross section tubes 2|.

Tubes 20 and 2i are provided with a multiplicity of closely spaced fins22 through which the tubes extend and to which they are bonded in theusual manner. In designs of the class, it is customary to either formthe header with separate tube plates which are removably secured to theheader caps or the outer surface of the headers are provided withthreaded apertures which register with the tubes for the reception ofthe expanding tool with which to expand the tube ends into the headersafter which the apertures are closed preferably by means of pipe plugs.These methods are too well known to require further description or torequire illustration in the present drawing.

Tubes 2i are provided with agitating strips which in their entiretiesare designated by reference character A. I have shown the preferred formof strip although many other well known designs may be used. Strips Aare first formed from flat stock, as illustrated in Figure and then theyare bent into the shape shown in Figure 4, the strips comprisingconnecting members 23 and spaced cross members 24 each having an opening25, the ends of which are out free forming strips 26, the strips beingbent outwardly as illustrated in Figure 4 so as to practically prevent astraight through path in the tubes.

When the strips are designed and bent as illustrated in Figure 4, verysmall straight through openings 21 and 28 are provided but theseopenings are not very effective for the passage of oil because the oilis diverted violently back and forth by members 23, 24 and 26, the oilbeing caused to violently impinge the walls of the tubes thus toincrease the heat transfer capacity of the tubes and provide meanswhereby when the oil is quite thick or viscous, it will not readily passthrough the tubes.

Clearly the resistance offered to the passage of chilled oil throughtubes 2| may be sufilcient to cause a pressure which will lift valve llso the oil will practically all pass through tubes 20 and since thesetubes have a limited heat exchange area in contact with the blast ofmoving air through the core, as indicated by single pointed arrows, theoil will be permitted to heat quickly after which heat transfer willtake place from the heated oil and heated air into the oil in tubes 2|.Thus the chilled stagnant oil in tubes 2| will be heated so in timevalve II will be permitted to close and all of the oil forced throughtubes 2| after which it, will be adequately cooled by the air blast andits contact with the fins and tubes.

In the present design, the headers form the upper and lower retainers ofan air duct. I provide plates 3H0 which are secured to the ends of theheaders having narrow flanges 3| which embrace the front and rear sidesof the headers and protect the corners of the fins. ''hetse plates formthe side members of the air In Figure 2 I have illustrated the directionof oil flow when the valve is closed by double pointed arrows.

It is generally the custom to force the blast of air between the finsand tubes by means of irontal pressure. It will be understood that mydevice may be used for cooling the oil on stationary engines by simplyproviding the device with an air moving fan similar to automobileradiators.

In Figures 6 and 7 I illustrate tubes 35 which are flattened and havingtherein an agitating strip comprising transverse members 36 havingopenings 31 therein and being connected together by means of connectingmembers 38, the strips being zig-zagged somewhat similar to that shownin Figure 4. This design of tube may be used in place of tubes 2| inFigure 2 and they may also be supplied as a substitute for tubes 2|wherein no agitating strips would be needed.

Aperture l2 permits some oil to pass through tubes 20 when valve I4 isclosed. Thus when the valve is closed and the oil is hot, some of itwill pass through tubes 20 and be cooled thereby.

Clearly many minor detail changes may be made in the present inventionwithout departing from the spirit and scope of this invention as recitedin the appended claims.

Having thus shown and described my invention, I claim:

1. A unitary oil temperature controlling device comprising spacedheaders having inlet and outlet connections in their rear sides andbeing operatively connected together by a number of rows of tubes, amultiplicity of closely spaced strip fins through which said tubesextend, whereby a blast of air may be forced between said tubes and finsfrom the front thereof, at least one front row of tubes being adapted tooffer little resistance to the flow of oil when chilled, the other tubesbeing adapted to offer great resistance to the flow of oil when chilled,a partition in one of said headers separating the low from the highresistance tubes and having a relief valve adapted to permit the oil topass through the low resistance tubes when it cannot pass through thehigh resistance tubes, said rear bank of tubes having therein agitatorsadapted to prevent a free flow of oil therethrough.

2. A unitary oil temperature controlling device comprising two spacedheaders having inlet and outlet connections in their rear sides andbeing operatively connected together by a number of rows of tubes, amultiplicity of closely spaced strip fins through which all of saidtubes extend and in metallic contact therewith, whereby a blast of airmay be forced between said tubes and fins from the front of the devicetoward the rear thereof, at least one row of tubes positioned at thefront of the device being adapted to offer little resistance to the fiowof oil when chilled, the other tubes being adapted to offer greatresistance to the fiow of oil when chilled, a partition in one of saidheaders separating the low from the high resistance tubes, a by-passvalve adapted to permit the oil to pass from the high resistance to thelow resistance side of said partition when it cannot pass freely throughthe high resistance tubes.

3. A device as recited in claim 2 including: a relatively smallpermanently opened aperture adapted to permit free passage of oildirectly from the high pressure to the low pressure side of thepartition.

HOWARD F. BRINEN.

